Kraton Arrma aluminum center diff case

[BashTillBroken]

I have the aluminum center diff case is my kraton and it still leaks any thoughts I believe i put all the shims and all that stuff that it came with

 

[SrC]

EXB or the RTR Alloy diff cup???
None of my RTR Arrma diff cups ever leaked for me. Have several of them. I only run them at the center diff.
Where exactly is it leaking from?
It can only leak at the 2 Gaskets or at the 2 O-rings.
Remember, if it is the RTR alloy diff version, you need the 2 extra included shims used. Proper orientation.
Blue Thread locker is used for the 8 screws. No oil should get into the screw hole threads. This can hasten loosening of those 4 screws. Leaking at the gaskets.
Food for thought.
A diff should NOT leak. Over time, if anything, the O-rings will wear out with use and will leak at the Output cups shafts. Onto the BB's.
If leaking at the gaskets, that is user assy. error. Usually more oil leakage than at the O-rings.
I run 60k/500k/30kRr FWIW. Most of my Arrma 6s basher rigs.

 

[BashTillBroken]

It’s the red one with the arrma logo don’t know if its the exb one don’t believe the package said exb it has the 8 screws it looks to be leaking from the dogbone cups ill put photos tomorrow ore later today when i have a chance
I believe it said to add extra shims and i did add them it there a rubber spacer im missing or something?

 

[Engineer]

The EXB outdrive shafts are thicker than the standard non-EXB shafts - so you need to match the proper diff case up with the internals.

Other than that, I would suggest applying some grease to the o-rings and make sure they are seated properly and also smear some diff fluid on the gaskets before screwing them down. Also helps hold the gaskets in position.

 

[BashTillBroken]

It doesn’t wiggle much but it does but all my shafts do is there a way to tell if it’s the exb one mine has the white arrma logo on it

 

[GraniteFox]

You may have missed an oring gasket when transferring from the standard diff or the seal broke on install. Just a guess. Sometimes they are coated and hard to see.

 

[SrC]

It’s the red one with the arrma logo don’t know if its the exb one don’t believe the package said exb it has the 8 screws it looks to be leaking from the dogbone cups ill put photos tomorrow ore later today when i have a chance
I believe it said to add extra shims and i did add them it there a rubber spacer im missing or something?

I was asking if you are running EXB LSD diffs or the RTR standard Open diffs? These use 2 different Alloy diff cups.

 

[BashTillBroken]

are you talking about those red o rings found one on my desk but i think its from one of my old spare parts diff

I was asking if you are running EXB LSD diffs or the RTR standard Open diffs? These use 2 different Alloy diff cups.

I’m using the stock one it came with two anti leak pads put both on maybe that’s the reason

 

[Engineer]

Standard/non EXB diff case

29mm EXB diff case:

Can you tell where it's leaking from?

 

[GraniteFox]

HH is still shipping the 29mm EXB with the cap head screws. ugh

 

[BashTillBroken]

Standard/non EXB diff case
View attachment 220976

29mm EXB diff case:
View attachment 220977

Can you tell where it's leaking from?

I have the standard one

 

[Engineer]

Can you tell where it’s leaking from? And are you sure it’s leaking versus excess fluid from overfilling?

 

[SrC]

^^^
+1
If Overfilled, then extreme pressure will blow out Oil past the O-rings in most cases.

 

[BashTillBroken]

It’s might be but it from the other side that i filled it up from its leaking out of the outdrivecup

 

[BashTillBroken]

^^^
+1
If Overfilled, then extreme pressure will blow out Oil past the O-rings in most cases.

I was doing it when I underfilled it too
Edit: it was leaking when it was underfilled too

 

[SrC]

Use a new set of O-rings, Greased well with a silicone "Grease", on the Output cup shaft also.
Starting all over.

 

[SrC]

It is real easy to overfill a diff. Especially if air remains along with too much oil. Aeration creates more pressure. Blows past the O-rings. It usually stops doing this at some point when the oil volume equalizes to its acceptable level. But creates a mess of oil at the BB's and Output drives. Attracting dirt in the process.

With the RTR 6s plastic diff cups, I release any excess diff Oil/pressure by removing the grub screw in the cup and rotate the diff outdrive cups a few turns, Oil will expel. When it stops, I replace the screw. A few rotations is all you need.
With the Alloy diff cups, you can't do this. There is No Grub screw.

Always fill your diffs slowly, It should be the slowest process of building the diff. Air needs to bleed out. DIff oil is thick, so it takes a while. Let it sit there for an hour.
I use a Shock Vacuum Pump for this. Speeds things up greatly. Tons of air rises. Visibly seen inside the Vacuum pump. Leaving air within, displaces the proper quantity of Oil. Diff will run much hotter.
I use my Tamiya Large shock pump religiously, Both shocks and Diffs.

 

[BashTillBroken]

Here are the photos

 

[Engineer]

My suggestion is to pull the diff out and examine it. Too hard to tell while it is installed - or just pull it and rebuild, paying careful attention to the o-rings and gaskets and hopefully that solves it.

 

[BashTillBroken]

My suggestion is to pull the diff out and examine it. Too hard to tell while it is installed - or just pull it and rebuild, paying careful attention to the o-rings and gaskets and hopefully that solves it.

Man I literally built it yesterday